An Emulation Framework for Wireless Structural Health Monitoring

Many competing approaches exist in literature in evaluating sensor network solutions, differing by levels of ease of use, cost, control and realism. Many existing works concentrate on simulating network protocols or emulating processing units at the machine cycle level. However, little has been done to emulate sensors and the physical environments they monitor. The main contribution of this work is the design of WiserEmulator, an emulation framework for structural health monitoring (SHM), which gracefully balances the trade-offs among realism, controllability and cost. WiserEmulator consists of two main components — a testbed of wireless sensor nodes and a software emulation environment. To emulate the excitation and response of piezo-electric transducers, as well as the wave propagation inside concrete structures, the COMSOL Multi-Physics software is utilized. Digitized sensing output from COMSOL is played back via a multi-channel Digital-to-Analog Converter (DAC) that is connected to the wireless sensor testbed. In addition to the emulation of concrete structures, WiserEmulator also allows users to choose from prestored data collected from field experiments and synthesized data. A user-friendly Graphical User Interface (GUI) is developed to facilitate intuitive configurations of experimental settings, control of the on-set and progression of the experiments, and real-time visualization of experimental results. We have implemented Wiser Emulator in MATLAB. This work advances the state of the art in providing low-cost solutions for evaluating Cyber Physical systems, such as wireless SHM systems.